One and two-stage regulators are used in a wide variety of applications to control the flow of compressed gas from a high-pressure side to a low-pressure side in a manner that provides gas pressures suitable for the appropriate use at the application (low-pressure) side of the regulator. Various industries with applications requiring two-stage high-pressure breathable air regulators include SCUBA applications, medical oxygen therapy, emergency medical services, fire fighting, environmental hazard response, search and air rescue, among others.
In all of these applications, the purpose of the regulator is to take a high-pressure gas source, e.g. an air cylinder, and deliver the air or other gas to the user at useable pressure. To accomplish this, the gas must pass through a pressure reduction regulator. In current practice, the first stage is placed on a yoke attached to the tank and the second stage connects to the mouth piece as shown in FIGS. 1, 2 and 3. The first-stage takes incoming high pressure gas from the cylinder and reduces it to an intermediate pressure that is greater than the ambient pressure. The second stage, which fits into the user's mouth or mask, receives the intermediate pressure from the two hose lines connecting to the first stage and reduces it to a usable ambient pressure. Two hose lines are used for redundancy.
FIG. 1 shows a photograph of a traditional yoke 100 manufactured by Johnson Outdoors Inc. under the SCUBAPRO® name which forms the first stage of a traditional regulator. An inlet 101 receives gas from a tank (not shown) typically at 3,000 psi. Dual lines 105 carry output gas at a reduced intermediate pressure, typically ranging from 120 to 180 psi. Knob 103 holds the yoke to the tank; a pressure gauge is connected via line 107 and buoyancy control is connected via line 109.
FIG. 2 illustrates an example of a traditional two-component regulator 200 (SCUBAPRO®) and described in U.S. Pat. No. 4,862,884 (see FIG. 1). First stage 201 of the regulator is connected to the second stage 203 via a hose 205.
FIG. 3 illustrates an example of a traditional two-component regulator 300 in operation used for SCUBA diving (SCUBAPRO®) and described in U.S. Pat. No. 7,171,980 (see FIG. 1). First stage 301 of the regulator is connected to the second stage 303 via a hose 305. The first stage 301 attaches to the tank, while the second stage 303 goes into the user's mouth.
FIG. 4 illustrates an example of a traditional flat-shaped piston 400 used in the first stage to regulate pressure in a traditional regulator (SCUBAPRO®) and described in U.S. Pat. No. 7,171,980 (see FIG. 4). This schematic view shows the forces acting on a valve poppet while in an open (top) and a closed (bottom) position during operation of the regulator. In the closed position (bottom), the pressure applied to the right side of the piston face, element 403, closes the piston against the valve poppet 401. In the open (top) position, when the pressure reduces, the piston moves into the containment area 407 and air pressure flows around the container wall 405.
There are numerous problems associated with traditional designs, depending upon the particular application. For example, in SCUBA applications, the extreme cold encountered at deep diving depths may cause the first stage of the pressure regulators to freeze up and malfunction. The brass and chrome coating materials tend to cause the poppet valve to stick in the open or closed position at these cold temperatures which endanger the life of the diver. Another issue with these designs is that improper use of the adjustment knob could also pose a danger by the end user accidently changing the pressure out of the safe operating pressure range. Typically, first stage regulators require two components and two lines for redundancy due to the safety concern of product failure.
Accordingly, it would be an advancement in the state of the art to provide a two-stage micro-regulator by reducing the size of the regulator and eliminating the adjustment nozzle through fixed pressure settings defined during the manufacturing process. It would be a further advancement in the state of the art to produce both the first and second stages in a single cylindrical component, which can fit inside a user's mask or mouth piece, which provides body heat, hence preventing freezing.